The present invention relates in general to mineral mining installation and, more particularly, to apparatus for controlling or adjusting the position of a mineral mining machine movable along guide means.
U.S. Pat. No. 4,045,089 describes apparatus of the type with which the present invention is concerned. This known apparatus comprises hydraulic piston and cylinder units coupled between brackets on a conveyor and connectors pivotably connected to the conveyor and linked to elongate beams guided on roof supports. The units can be extended or retracted to tilt the conveyor and hence a guide thereby to control the position of a machine such as a plough displaceably mounted on the guide. There is a direct relationship between the stroke of the units and the angle of tilt. The elongate beams serve to guide at least the roof supports during shifting and also act as jib-like stabilizers for bracing the system during the tilting control. The units are coupled to the connectors with the aid of ball-and-socket joints which provide flexibility enabling the apparatus to cope with the prevailing conditions in the mine working.
U.S. patent application Ser. No. 373,548 filed Apr. 30, 1982 and assigned to the same assignee as the present application discloses further developments of the apparatus described in U.S. Pat. No. 4,045,089 and is herein incorporated by reference. In accordance with the apparatus described in the aforementioned U.S. patent application Ser. No. 373,548 the units are inverted in relation to the arrangement described in U.S. Pat. No. 4,045,089 with the cylinders coupled via ball-and-socket joints at the upper ends to the brackets on the conveyor. Inter alia, this is advantageous since the units can be quite steeply inclined and take up less space.
A general object of the present invention is to provide a further improved control apparatus.